1912 7 10 Gasoline GMC Trucks Electric General Motors Truck Company Pontiac, Michigan THE HORSELESS AGE Vol. 30, No. 2 July 10, 1912 9″x12″ page 53
1912 8 21 ELEC GENERAL MOTORS TRUCK COMPANY THE HORSELESS AGE 9″×12″ Back cover
1912 9 4 ELEC GMC TRUCKS GASOLINE ELECTRIC THE HORSELESS AGE 9″×12″ page 26